Roller fore-aft adjustment for a vehicle seat

Abstract

A fore-aft adjustment, for a vehicle seat, employing rollers. The vehicle seat includes a seat assembly coupled to a support assembly. The support assembly includes a first portion affixed to the vehicle and a second portion affixed to the seat assembly. One of said first or second portions includes a plurality of roller structures having rotational axes which are substantially vertical. The other of said first or second portions includes guide members, the roller structures rotatably engaging the guide members to provide for longitudinal movement of the seat assembly with respect to the vehicle.

I claim: 
     
       1. A fore-aft adjustment and support mechanism for a vehicle seat, comprising: upper base means; fixed, lower base means disposed closely below and out of weight-supporting contact with the upper base means, said upper base means being movable fore-aft relative to the lower base means; a plurality of parallel fore-aft guide rail means fixed to one base means and spaced laterally from and out of weight-supporting contact with the other base means, each rail means having a flat, fore-aft weight-bearing surface; a plurality of guide roller means journaled on said other base means on parallel generally upright axes offset laterally from the respective rail means and cooperative with said respective rail means to carry the entire weight of the upper base means on the lower base means, each roller means including a flat, circular radial face overlapping and engaging flatwise with its associated rail means surface to accommodate total downward loading on the mechanism, whereby the roller means turn about their respective axes by virtue of said engagement with said respective guide rail surfaces as the two base means move relative fore and aft; and releaseable means for selectively locking the two base means against said relative movement fore and aft. 
     
     
       2. The mechanism of claim 1, in which each guide rail surface is flanked by an adjoining, fore-aft guide edge, and each roller has an annular guide portion adjoining and coaxial with its radial face and rollably engageable with the associated guide edge to confine the two base means against relative lateral movement during said relative movement fore and aft. 
     
     
       3. The mechanism of claim 2, in which each guide rail is a laterally directed flange having the aforesaid flat surface as well as a second flat surface parallel to and spaced vertically from the first flat surface, both of said surfaces adjoining said guide edge, and each roller has an annular groove providing the aforesaid radial face as well as a second radial face opposed to said first radial face and flat-wise engageable with the aforesaid second flat surface, the base of said groove providing the aforesaid annular guide portion. 
     
     
       4. The mechanism of claim 3, in which each guide rail flange and its associated roller means groove are so relatively configured as to afford substantially large bearing areas between the associated flat surfaces and radial faces. 
     
     
       5. The mechanism of claim 3, in which each guide rail flange and its associated roller means groove are so relatively configured that the flange surfaces are substantially parallel to each other, the radial faces on each roller means are substantially parallel to each other, the flanges closely fitting their respective grooves, and the guide edges extending substantially to the bases of the respective grooves. 
     
     
       6. The mechanism of claim 3, in which the plurality of roller means is arranged as a front pair of laterally spaced apart roller means and a rear pair of laterally spaced apart roller means spaced rearwardly of the front pair, and means is provided on one base means intermediate the front and rear pairs and extending toward the other base means for engagement with said other base means to prevent vertical separation of one base means from the other in the event of the application of excessive upward forces causing failure of the interengagement between the roller means and the guide rail means. 
     
     
       7. The mechanism of claim 6, in which said last-named means is carried by the base means that carries the roller means and extends toward and is engageable with the guide rail means for the purpose aforesaid.